The Justice Department is investigating whether longtime Republican fundraiser Elliott Broidy sought to sell his influence with the Trump administration by offering to deliver U.S. government actions for foreign officials in exchange for tens of millions of dollars, according to three people familiar with the probe.

As part of the investigation, prosecutors are scrutinizing a plan that Broidy allegedly developed to try to persuade the Trump government to extradite a Chinese dissident back to his home country, a move sought by Chinese President Xi Jinping, according to two of the people.

They also are investigating claims that Broidy sought $75 million from a Malaysian business official if the Justice Department ended its investigation of a development fund run by the Malaysian government. The Malaysian probe has examined the role of the former prime minister in the embezzlement of billions of dollars from the fund.

A Justice Department spokeswoman declined to comment. Christopher Clark, an attorney for Broidy, said in a statement: “Elliott Broidy has never agreed to work for, been retained by nor been compensated by any foreign government for any interaction with the United States Government, ever. Any implication to the contrary is a lie.”

Broidy’s alleged activities were detailed in news reports earlier this year that cited hacked emails. The Los Angeles-based venture capitalist, who served as top fundraiser for the Republican Party and President Trump, has said that allegations against him are an effort by his enemies to smear him.

Rudolph W. Giuliani, an attorney for Trump, said he had no knowledge of any request for records related to Broidy. The White House referred a request for comment to the Republican National Committee, which declined to comment.

In recent weeks, prosecutors with the Justice Department’s public integrity section — which examines possible political and government corruption — have sought documents related to Broidy’s business dealings.

Among the information sought by investigators are details about Broidy’s work on behalf of and interactions with the Chinese and Malaysian officials, according to two people familiar with the document requests.

As part of their efforts, prosecutors have subpoenaed casino magnate Steve Wynn, the former RNC finance chairman and longtime Trump friend, for copies of records and communications related to Broidy.

An attorney for Wynn, Reid Weingarten, declined to comment, saying only that Wynn is cooperating with the Justice Department.

“Steve Wynn is completely cooperating with the investigation and he certainly has no reason to believe that anyone acted improperly in anything he knew about or was involved in,” Weingarten said in a statement.

Wynn was tapped by Trump to serve as the RNC’s lead fundraiser after the election. Earlier this year, he stepped down from that post and from his executive role at his resort company after reports of sexual misconduct. Wynn has denied the allegations of inappropriate behavior.

The public-integrity probe is the latest legal challenge for Broidy, who helped corral big donors to support Trump’s presidential campaign, throwing a lavish fundraiser for the then-nominee at his Los Angeles-area home during the 2016 campaign. After the election, he was appointed to serve as a national deputy chairman for the RNC.

Broidy sought to parlay his party role and connections to the White House and on Capitol Hill in pitches to foreign governments, according to a person with direct knowledge of his activities.

In April, he resigned from his RNC position in the wake of a report that he had paid a former Playboy model $1.6 million in exchange for her silence about a sexual affair. Trump’s personal attorney, Michael Cohen — another RNC fundraiser — helped arrange the settlement, Broidy acknowledged.

Cohen is under investigation by federal prosecutors in Manhattan who are examining whether he fraudulently obtained millions of dollars in loans and whether his efforts to squash negative stories about Trump during the campaign violated election law.

Broidy’s business dealings captured the attention of investigators for special counsel Robert S. Mueller III, who asked at least one witness about Broidy’s activities, according to a person familiar with the matter.

Broidy’s attempts to solve high-level headaches for the Chinese and Malaysian governments were first reported this spring by the Wall Street Journal and the New York Times, which cited in part a cache of hacked emails.

Broidy has said the documents were stolen by enemies seeking to ruin his reputation.

“This whole narrative is a fabrication driven by hackers who want to undermine me,” Broidy said in a statement to the Times. Earlier this year, he filed a lawsuit against Qatar and Qatari officials, alleging that the country hacked his email accounts in retaliation for his allegations that Qatar supports terrorists. A spokesman for the Qatari government has called the suit “without fact or merit,” and a federal judge dismissed the country as a defendant in the suit earlier this month, citing jurisdictional issues.

The Journal reported in March that, according to a draft contract, Broidy and his wife, Robin Rosenzweig, were seeking $75 million from Malaysian businessman Jho Low if federal prosecutors dropped their investigation into a Malaysian state investment fund.

The Justice Department has filed civil suits claiming $4.5 billion in public money was misappropriated from the fund, 1Malaysia Development Berhad, seeking to claim a portion of those assets. Last month, Malaysian authorities charged former prime minister Najib Razak with embezzling billions in public money from the fund.

Clark, the Broidy attorney, told the Journal that Rosenzweig’s firm had been hired to provide strategic advice to Low, adding that “at no time did Mr. Broidy or Ms. Rosenzweig, or anyone acting on their behalf, discuss Mr. Low’s case with President Trump, any member of his staff, or anyone at the U.S. Department of Justice.”

The Times reported in April that Broidy had explored ways to force Chinese exile Guo Wengui to leave the United States. The billionaire businessman had fled China in 2014 as he was facing arrest for a range of charges, including corruption. Guo has said the allegations were fabricated by a government that wants to silence him.

Since his arrival in the United States, Guo has publicly detailed allegations of corruption in the Chinese ruling party.

The Times reported that Broidy drafted a plan to enlist Emirati officials to pressure the United States to turn over Guo. In his statement to the newspaper, Broidy said he “never had a strategy or plan regarding Mr. Guo nor was there any compensation given or even discussed.”

Broidy’s alleged efforts to push for Guo’s extradition came after Wynn separately helped deliver a message from the Xi government seeking to have the dissident returned to China, according to a person familiar with the effort.

Wynn, who has contacts with Chinese officials because of his business interests in Macau, hand-delivered a letter to Trump seeking Guo’s deportation, The Journal reported last year. A spokesman for Wynn Resorts has said that the report about Wynn’s role was false.

At the time, the president expressed interest in assisting the Chinese but was met with resistance by senior law enforcement officials, according to the person.